1. Field of the Invention
The present invention is directed to compositions and methods of inhibiting the activity of the enzyme aromatase with dietary supplements. In particular, the invention is directed to compositions and methods of inhibiting the activity of aromatase using a composition comprising at least one of the dietary supplements astaxanthin, black cohosh, echinacea, and phytosterols.
2. Related Background Art
There is evidence that estrogen and related estrogenic compounds have a role in the development of cancers in women, in particular, breast cancer. See, for example, Clemons et al., ESTROGEN AND THE RISK OF BREAST CANCER, The New England Journal of Medicine, Vol. 344, No. 4, pp. 276-285 (2001). In addition, it is known that the enzyme aromatase plays a role in the synthesis of estrogen. In particular, aromatase converts C19 androgens, such as androstenedione and testosterone, into estrogenic steroids, such as estrone and 17-β estradiol.
Compounds that inhibit the activity of aromatase are known, and have been suggested or used as a treatment for breast cancer. For example, Gross et al., AROMATASE INHIBITORS IN THE TREATMENT AND PREVENTION OF BREAST CANCER, Journal of Clinical Oncology, Vol. 19, No. 3, pp. 881-894 (2001), disclose steroidal and non-steroidal aromatase inhibitors that have been tested in phase III trials as second line treatments of postmenopausal hormone-dependent breast cancer, and may prove superior to tamoxifin. Compounds identified as aromatase inhibitors include aminoglutethimide, a first generation, non-steroidal aromatase inhibitor. Other compounds identified as aromatase inhibitors include the second generation aromatase inhibitors, rogletimide and fadrozol, which are non-steroidal, and formestane, which is steroidal, and the third generation aromatase inhibitors, anastrozole, letrozole, and vorozole, which are non-steroidal, and exemestane, which is steroidal.
Although the third generation inhibitors are less toxic than the first and second generation compounds, they still present toxicity issues. In particular, Goss et al. found that the third generation inhibitors could cause nausea, vomiting, hot flashes, fatigues and headaches. Therefore, a need exists for an aromatase inhibiting composition having lower toxicity than that of prior art aromatase inhibiting compositions. The present invention provides such compositions and a method of inhibiting aromatase with the compositions of the invention.